Recent years, a trend of consumed energy is increasing due to high and multi-function of handheld device such as wearable information terminal. However, it is difficult to have a battery with larger capacity in view of the size and weight of the handheld device.
For example, the reference 1 discloses, by detecting usage of a user and in accordance to the detected usage of the user, a wrist watch type information terminal setting one of first mode restricting a display of information to display means and forbidding input operation to input means, second mode allowing the display of information to the display means and forbidding input operation to the input means, or third mode allowing the display of information to the display means and input operation to the input means, to reduce the energy consumption and to prevent any incorrect operation as well as to prevent any circumstances where operator's view is narrowed by keeping operating the information terminal.
In recent years, a touch panel, which allows easy operation with a touch of a finger on a screen, is often used for handheld devices such as wearable information terminals. Therefore, as the handheld device itself will be covered with the operating finger, it may be difficult to recognize face to detect the usage of the user as described in the reference 1. Further, with a small wearable information terminal, the screen will be covered with the operating finger and it may be even more difficult to operate.
Therefore, it is an object of the present invention to provide a wearable information terminal which enables to reduce energy consumption and to improve the operability.